Greener method found for oil extraction

A research team led by the University of Bristol has come up with a new way to treat carbon dioxide so that it can be used in efficient and environmentally friendly methods for extracting oil.

The technology can also be used to reduce the environmental damage caused by every day industrial processes such as food processing and the manufacture of electronics.

The researchers developed a soap-like soluble additive for CO2 that turns it into a viable solvent for commercial-scale enhanced oil recovery to increase the amount of crude oil that can be extracted from oil fields.

CO2 offers an efficient, cheap, non-toxic, non-flammable and environmentally responsible alternative to conventional petrochemical solvents. Even water as a solvent for example, comes with its own set of problems; after being used to flush out oil from rocks it then requires cleaning before it can be used again, whereas liquid CO2 can be re-used immediately.

Liquid CO2 is useful in oil extraction as it can flow through rock more easily than water. It is being used increasingly to replace common petrochemical solvents because it requires less processing and it can be easily recycled. The difficulty has been that in order to operate effectively as a solvent, CO2 needs additives, many of which are damaging to the environment.

The research has developed a solution to this with the new additive, surfactant TC14. It contains no fluorine and is a harmless hydrocarbon, according to the researchers.

One of the research bodies on the team was the University of Pittsburgh, led by Professor Bob Enick. He said: "The quest to find a chemical capable of modifying the properties of CO2 to make it suitable for widespread use as a solvent in enhanced oil recovery has been long.

"Previous advances have involved surfactants containing fluorine, which although highly soluble in CO2, are very environmentally damaging. The new additive, surfactant TC14, contains no fluorine at all and is a harmless hydrocarbon."

The paper published in the Langmuir is the first to come from Sans2d, one of seven new neutron instruments built at the ISIS second target station, a £145 million expansion to the facility completed last year. It is also one of the first to be published using data collected at the new target station.

Science and Universities minister David Willetts said: "This shows what science can do for the environment.

It's why the Government has protected the science budget. In particular it shows how financing core science facilities can lead to many different projects with valuable applications." Alison Brown